Camp 4 is a great option if you can't get a reservation 5 months ahead. We showed up around 8am and had no problem getting a spot (we couldn't showed up at 8pm, there were plenty of spots in late May). The registration process was a bit confusing and unintuitive - don't forget to grab a slip out of the box after you pay with the QR code. Other than that, location is perfect, right next to Upper Falls trailhead and others too. All our neighbors were cool, almost felt like a mini Woodstock/Coachella. Definitely coming back here again!